C. French defeats in Haiti ruined Napoleon's plan to build an empire in America.
Napoleon decided that holding a empire outside Europe would be too costly, drain too much resources and spread his troops out too much. He decided to drop most of the colonies & sell the Louisiana to the US not only as to be able to have more money to fund his wars, but also to give the UK a rival for the future.
~
Garrod hypothesized that individuals who could not metabolize protein could not produce the enzyme in their bodies. He was the first to identify the condition as a genetic disorder. Others thought it was caused by a bacterial infection. He came to this conclusion by noticing that the disease was more common in families where marriage between relatives was common.
The system of law you seek is "<span>sharia"
</span>
So every government can have a set of rules in their area without having conflict.